1. Field of the Invention
This invention relates to a method of cultivating flowering plants. More particularly, this invention relates to a method of cultivating flowering plants that controls the forms of plant organisms by controlling light quality of cultivating light, to enable, e.g., dwarfing to make small the height of a plant.
2. Description of the Related Art
In recent years, there is an increasing demand for flowering plants cultivated in pots so that they can be admired on tables. With regard to flowering plants in such pot cultivation, it is commonly desired to make their plant organisms small in size. For this purpose, in the pot cultivation, the plant organisms are made small usually by a method in which a dwarfing agent such as uniconazole is sprayed on the surfaces of leaves. The DIF method is also employed, which utilizes differences in temperature between night and day.
The use of dwarfing agents, however, causes anxiety about bad influence on the human body and environment. Accordingly, it is sought to dwarf flowering plants in the pot cultivation without using dwarfing agents.
Meanwhile, when flowering plants are cultivated in pots, it is also sought to enable control of the number and size of flowers, the density of florets that constitute a flower cluster, and the number and size of bracts.
As one of methods for the dwarfing and other morphological control of flowering plants, it is intended to control light quality of cultivation light, which is so attempted in recent years in order to control the growth of fruits and vegetables or green vegetables. However, how the light quality affects plants is in a great variety depending on not only various factors such as wavelength distribution of the light, light intensity and irradiation time but also the type of plants. Hence, it is not easy to find out cultivation conditions under which any desired types of plant organisms are dwarfed to have the desired forms suitable for the pot cultivation. Thus, under existing circumstances, no dwarfing cultivation is carried out by light quality control also in respect of flowering plants such as petunias, geraniums and poinsettias.